Supplements for rugby players

By Tom Francis·Updated 2026-09-03·3 sources·Editorial policy

Start with what a claim actually is

In the UK, a food supplement can only make a health claim that has been authorised, and the authorised list is public. That single fact sorts the shelf faster than any review.

If a product is sold on an outcome that has no authorised claim behind it, the seller is either making it up or leaning on research that has not been assessed. Neither is a reason not to buy, but both are reasons to know which you are doing.

The four products, ranked by how much they can actually claim

Magnesium comes first on claim strength rather than on marketing. It has authorised claims for normal muscle function, protein synthesis, reduction of tiredness and fatigue, electrolyte balance, energy metabolism and nervous system function, all available at a serving providing at least 15 percent of the 375mg reference intake.

Omega 3 has one realistic claim: EPA and DHA contribute to normal heart function at 250mg a day combined. Marine collagen has none of its own and depends on the vitamin C alongside it, which carries a claim for normal collagen formation. Lion's mane has no authorised claim of any kind and is bought on curiosity and early research.

What club players are sold that does not stand up

Cramp products lead the list. There is no authorised cramp claim for magnesium or for anything else, and cramp in the second half is more likely a neuromuscular fatigue problem than a mineral one.

Joint products are next. No authorised joint claim exists for omega 3 or for collagen, despite both being marketed on it constantly. And anything sold on protecting a player's brain in a collision sport should be walked away from immediately.

What actually matters more than any of it

Sleep, total food intake, and the design of the training week. A player getting six hours sleep and eating two meals a day through pre season has problems that no capsule addresses.

Supplements are worth what they are worth once the basics are handled: covering a nutrient reference intake reliably, filling a dietary gap like oily fish, or trying something with an interesting literature behind it at a price that does not matter if it does nothing.

The budget question

Priced against real products, Futuro Labs Lion's Mane is the cheapest of the four at 13p a day and Futuro Labs Marine Collagen the dearest at 28p.

Club rugby is played by people paying subs, buying boots and driving to away games. A supplement stack that costs more than the subs is not a serious proposition.

Priced properly, this is a small line item. Magnesium at 22p a day, omega 3 at 17p, collagen at 28p and lion's mane at 13p come to 80p a day for all four, which is under 25 pounds a month. Most of the cost in this category comes from buying products whose active content is a fraction of what the front of the pack implies.

The questions to ask before buying anything

Five questions cover most of it and none needs any specialist knowledge.

What is the active content per serving, and is it printed? What percentage of a reference value does that represent? Is there an authorised claim for this outcome at all, or is the product being sold on something that has never been assessed? What does it cost per day rather than per tub? And, for anyone who could be tested, is it batch certified rather than merely lab tested for purity?

A product that answers all five well is worth considering. One that cannot answer the first has removed the ability to compare it, and one whose selling point fails the third is being marketed outside what the rules allow. That is a filter that removes a large share of the shelf before price is even considered.

Where to go next

• Magnesium for rugby playersCramp, sweat loss, evening training and how much a player actually needs.
• Marine collagen for rugby playersTendons, scrum loading and the vitamin C that carries the claim.
• Omega 3 for rugby playersEPA, DHA, the 250mg threshold and the club diet that never includes oily fish.
• Banned substances and batch testingWhat batch certification means and what lab tested for purity does not.
• How to read a supplement labelThe method for comparing two products when the packs tell you nothing.

Questions players ask

Sources

• EFSA register of nutrition and health claims
• Food supplements guidance, gov.uk
• National Diet and Nutrition Survey, gov.uk